An absorbent article such as a sanitary napkin, pantiliner, diaper, incontinence pad, or inter labial article typically comprises a liquid permeable cover on its body facing side, a barrier on its garment facing side, and an absorbent core in between. A common problem with absorbent articles is bunching and deformation of the article due to movement of the person wearing it. Bunching and deformation in turn impair the ability of the article to absorb exudates from the body.
Several suggestions for solving the problem of bunching have been made. For example, U.S. Pat. No. 4,886,513 to Mason, Jr. et al. discloses a pad comprising a flexibly stiff reinforcing member to maintain the pad's shape. The reinforcing member may be for example a strip of polyethylene extending around the periphery of the pad.
U.S. Pat. No. 5,609,588 to DiPalma et al. and U.S. Pat. No. 5,803,920 to Gilman et al. relate to the use of a resilient layer of non-absorbent foam in a sanitary napkin. The resilient layer is said to resist bunching during use of the napkin, so that the napkin has reduced twisting and bunching.
U.S. Pat. No. 5,387,208 to Ashton et al. discloses an absorbent article with an absorbent core having improved integrity by virtue of the presence of a primary core integrity layer. The primary core integrity layer is made of a liquid impervious mesh of thermoplastic material, preferably a hot melt adhesive.
U.S. Pat. No. 4,973,325 to Sherrod et al. relates to an absorbent article having a transfer member positioned between two side-by-side absorbents. The transfer member is said to allow the absorbent article to flex in the middle and conform to the body of the wearer, thereby reducing bunching.
U.S. Pat. No. 5,575,786 to Osborn recites in claim 1 a sanitary napkin comprising absorbent portions aligned along the longitudinal centerline of the napkin and peripheral portions aligned adjacent to the absorbent portions. The peripheral portions have a different stiffness than the absorbent portions, and the difference in stiffness is claimed to substantially prevent bunching of the napkin when the napkin is subjected to lateral stresses.
Despite these attempts at maintaining the physical integrity of absorbent articles, an absorbent article having even better anti-bunching properties is needed. Applicants have identified a class of such absorbent articles. Specifically, the present invention provides an absorbent article, such as a sanitary napkin, pantiliner, diaper, incontinence pad, or an interlabial article, in particular a thin absorbent article, comprising in sequence a liquid permeable cover, an absorbent core, and a barrier, having a caliper of less than 0.2 inches, a length of less than about 8 inches, a width of less than about 4 inches, and a Bunching Resistance of at least about 205 g. Preferably, the absorbent article comprises an absorbent core comprising at least two absorbent layers having different Gurley Stiffnesses.